When an aircraft dies.
The confounding elements and those that distinguish this particular loss, is the aircraft`s so far known behaviour in its dying throes. So far the link between its trajectories, both in the lateral and vertical planes and its electronic emissions, do not present any previously fitting or comparable pattern.
It will be sometime before any substantive evidence emerges which may assist in formulating any reasonable speculation as to the circumstance(s) which may have led to its demise.